Water-preservation mining is one of the most important parts of the ‘Green Mining’ technology system,which can realize the effective regulation of groundwater resources by controlling strata movement,changing passive prevention and governance of water disasters to active conservation and utilization of groundwater resources and thus obtaining coal and water simultaneously in mining.The concept of water-resistant key strata further enriches the content of the key stratum theory and provides a theoretical basis for water-preservation mining.In order to realize the idea of water-resistant key strata as a guideline in the design of water-preservation mining and engineering applications,the conditions for discrimination in the process of water-resistant key strata,we have presented a mechanical model,as well as its corresponding computer program,based on a large number of theoretical analyses and field measurements,as well as on a comprehensive consideration of the position,structural stability and seepage stability of key strata.Practical engineering applications indicate that this discrimination method and its corresponding computer program on water-resistant key strata are accurate and reliable and can satisfy the actual design needs of water-preservation mining and thus have instructional importance for water-preservation mining in mining areas lacking water. Water-preservation mining is one of the most important parts of the ’Green Mining’ technology system, which can realize the effective regulation of groundwater resources by controlling strata movement, changing passive prevention and governance of water disasters to active conservation and utilization of groundwater resources and thus obtaining coal and water simultaneously in mining. The concept of water-resistant key strata further enriches the content of the key stratum theory and provides a theoretical basis for water-preservation mining. order to realize the idea of ​​water-resistant key strata as a guideline in the design of water-preservation mining and engineering applications, the conditions for discrimination in the process of water-resistant key strata, we have presented a mechanical model, as well as its corresponding computer program, based on a large number of theoretical analyzes and field measurements, as well as on a comprehensive consideration of the position, structural sta bility and seepage stability of key strata. Practical engineering applications that that discrimination method and its corresponding computer program on water-resistant key strata are accurate and reliable and may have the actual design needs of water-preservation mining and thus have instructional importance for water -preservation mining in mining areas lacking water.